Although not every thinker is innately susceptible to the pitfalls of radical skepticism and/or nihilism, there is a constant danger present to each and every thinker-- a vicious, infinitely regressive downward and inward spiral of insatiable analysis that has no end, except, for those unfortunate philosophers with weak intellectual constitutions, the abyss.

Consider the following excerpt from §1 of Nietzsche's The Gay Science:

Gradually, man has become a fantastic animal that has to fulfill one more condition of existence than any other animal: man has to believe, to know, from time to time why he exists; his race cannot flourish without a periodic trust in life—without faith in reason in life.

In many serious philosophers, this instinct is already inveterate and subconsciously established. They assume, right from the start, not only that this condition must be fulfilled, but also that it can be fulfilled. They do not scrutinize the condition itself, nor do they consider the possibility that there is no reason why he exists, nor reason in life at all.

Some philosophers, however, for one reason or another, fail to successfully fulfill this condition in their own minds. It may be a matter of over-analysis: the compulsion to continue asking "why" of popularly accepted axioms and fundamental truths that do not lend themselves to further dissection or explanation (leading to radical skepticism). It may be a matter of confusion: the inability to reconcile conflicting paradigms that, to the subject, each seems intuitively true enough that it should not be wholly discarded, even though it defies other paradigms that also fit the subject's intuitive criteria. Confusion can lead to insufferable intellectual frustration, and even the total abandonment of all thoughts and ideals (nihilism).

Whatever the reason, the point is simple: it is possible for even a rational thinker to lose faith in reason altogether. It is this psychological state in which I am interested: the absence of faith in reason. I offer this psychological state as a possible conceptualization of Nothingness: an epistemic abyss.

This abyss can consume, but it can also motivate. Nietzsche is astute and on target with his assessment of this particular human condition for living: man has to know why. Even the radical skeptic or nihilist can recover, and the suffering he feels in his epistemic abyss may just be the motivation that compels him to re-evaluate his intellectual approach and attempt to escape from it.

sorry, but it seems i have nothing (ha) to add. i've always felt radically skeptical, and nothingness is a type of truth for me. it is beautiful and alluring, something that makes more sense than existence.